Strategic advancement of the Korean table grape breeding program for consumer-preferred cultivars

Abstract

In Korea, summer rainfall and comparatively less favorable growing conditions than major grape-producing countries have influenced the direction of table grape breeding. Until around 2010, the primary objective of the Korean grape breeding program was to develop interspecific hybrids combining the environmental adaptability of American species with the superior fruit characteristics of European species. Interspecific hybrid cultivars such as ‘Campbell Early’ and ‘Kyoho’ were widely used as parental materials in the breeding program.

With increased exposure to imported grapes, consumer preferences shifted toward seedless cultivars with non-slip berry skin that can be eaten whole without peeling or removing seeds. Consequently, breeding targets expanded beyond large berry size, high soluble solids content, and attractive appearance to include more refined fruit quality traits.

Current breeding objectives emphasize genetically seedless cultivars with firm flesh, strong berry–pedicel attachment, and reduced skin astringency. The breeding program utilizes crossing populations such as ‘Tano Red’ × ‘Ruby Seedless’, as well as approximately 800 germplasm accessions. Using these materials, fruit traits phenotyping, genome-wide association studies (GWAS) and QTL analyses are performed to identify associated loci. SNP-based markers related to seedlessness are applied in the breeding program, while markers associated with other traits are being validated across germplasm resources.

In addition to fruit quality traits, bud fruitfulness and stable coloration have been incorporated as breeding objectives, and breeding populations are being developed with continuous data accumulation. Through the refinement of breeding objectives, intensive phenotyping, and routine SNP-based selection, the Korean table grape breeding program continues to advance toward the development of consumer-preferred cultivars.

Acknowledgements

This work was carried out with the support of Cooperative Research Program for Agriculture Science & Technology Development (Project No. PJ01774201), Rural Development Administration, Republic of Korea.